Diaphragm pumps



J. REITZ DIAPI-IRAGM PUMPS Dec. 1 5, 1964 Filed Aug. 25, 1961 [n ventorlfo-warms ,Wezz BY Attorney United States Patent() 3,161,142 DIAPHRAGMPUMPS .iohannes Reitz, Neckarsulm, Germany, assigner to General MotorsCorporation, Detroit, Mich., a corporation of Delaware Filed Aug. 25,1961, Ser. No. 133,956 Claims priority, application Germany Sept. 10,196i) Claims. (Cl. 1113-150) This invention relates to diaphragm pumpsand in particular to diaphragm fuel pumps for internal combustionengines. By means of the invention the construction of a diaphragm fuelpump can be simplified and reduced in cost through the employment ofcomponents which reduce the machining and die-casting operationsrequired in fuel pumps commonly in use hitherto.

In a diaphragm pump according to the invention the pump casing consistsof two sheet metal cup members secured together at their rims by acrimped flangerjoint to` form a sealed casing, one cup member havingsecured thereto a support member for the pump actuator members.

The connection of the rims of the two cup members is also employed tosecure between the rims the pump diaphragm, such connection alsoensuring an hermetic seal between the two cup members.

According to a further feature of the invention the support member forthe actuator members of the pump is made of plastics material and ispress fitted into one of the cup members; the support member may beadditionally secured to the cup member by adhesive.

The scope of the invention is defined by the appended claims; and theinvention and the method by which it is to be performed are hereinafterparticularly described with reference to the accompanying drawings, inwhich:

FIGURE 1 is a section through a diaphragm fuel pump according to theinvention secured in an opening in the block of an internal combustionengine;

FIGURE 2 is a View in the direction of the arrow 2 of FIGURE 1; with thepump removed; and

FIGURE 3 is a sectional view taken in the direction of the arrows 3 3 inFIGURE l.

The fuel pump shown in the drawings comprises two cup members 10, 11pressed from sheet metal, one member -forming the pump chamber 12 inwhich are arranged valves 13 and 14. The valves are of similarconstruction each comprising a housing 15 within which is a valve disc16 and a spring 17. The valves 13 and 14 are mounted in the chamber 12by pressing their respective housing rims 18 into recesses 19 and 20 ofthe cup member 10 so that they abut shoulders 21 and 22 respectively.The valves 13 and 14 are arranged so that one valve 13 acts as an inletvalve and the other valve 14 as an outlet valve, as indicated by thearrows on the drawing. A plate 25 secured by a rivet 26 to the cupmember 1i) secures the valves 13 and 14 against dislodgement from theirrespective recesses.

The two cup members 1t), 11 are secured together by crimping an annularrim tiange 3) on the cup member 1t) over a corresponding liange of theother cup member 11, the peripheral portion 31 of diaphragm 32 beingclamped between the two rim flanges. A disc 33 is secured to one side ofthe diaphragm 32, and a cup-shaped pressing or inner cup member 34 issecured to the other side, by means of a rivet 35.

The cup member 11 forms a housing for the actuator members of the pumpand for this purpose the base of the` cup member 11 has an opening 36with a neck 37 into which is press-fitted a support member 3S for thepump actuator members. The support member 38 may alternatively oradditionally be secured in the cup member 11 3,161,142 Patented Dec. 15,1964 ice by adhesive and is preferably made of plastics material such asphenolic resin. A collar 39 on the support member 38 abuts against theinner face of the cup member 11 and a plunger 40 is slidably mounted ina longitudinal bore of the support member. Mounted on the support member38 for rotation about spindles 42 mounted on the support member are tworocker levers 41, the inner ends 43 of which overlap each other and haveslide faces which abut the inner end of the plunger 40.

The outer ends 44 of the rocker levers 41 have slide faces which engagethe in-turned edge 45 of the inner cup member or cup-shaped pressing 34;and a fustroconical spring 48 is arranged between the pressing 34 andthe support member 38 so as to press the inner ends 43 of therocker-levers 41 on to the plunger 40 so that the outer end of thelatter engages with a cam 50 (shown in dotted lines) of the enginecamshaft. The edge 45 does not contact the collar 3Q as is seen inFIGURE 1.

The support member 38 has therein a cavity 51 with end stops faces 52,53 for a snap ring 54 mounted on plunger 40. In the uninstalledcondition of the pump the spring 48 presses the snap ring 54 against thestop 52 so that the plunger is fixed when in transport or in storage.The space within the cup member 11 is vented to atmosphere by way ofholes 23.

In order to enable the pump to be iitted to an engine block 55 thesupport member 38 has a cylindrical section 56 with an approximatelysemi-circular section transverse groove 57 the diameter of which is thesame as the outer diameter of the shank of a securing bolt 58 (FIGURE2). After the insertion of the bolt 58 the position of the pump withreference to the camshaft 50 is iixed. A slot 60 extending transverselyof the bolt 58 is provided in the engine block 55 and the pump issecured by tightening up the bolt 58. A sealing ring 62 of rubber orlike material seated in a groove 61 on the support member 38 seals thepump to the block so as to prevent the escape of oil from the engineblock.

Rotation of the engine-driven cam 5G effects reciprocation of theplunger 40 so that the diaphragm 32, during movement of the cam 50 fromits high point, as shown in FIGURE l, to its low point, will be moved tothe right as shown in FIGURE l, under the pressure of spring-48, thesucceeding movement of the plunger 40 acting through the ends 44 oflevers 41 on the edge 45 of the pressing 34 to restore the diaphragm 32to the position shown in FIGURE l against the action of spring 48 andthe fuel being drawn into the pump chamber 12 by way of the intake valve13 and expelled by way of the outlet valve 14 during successivereciprocations of the plunger 4i) of diaphragm 32.

I claim:

1. A diaphragm pump having a casing, a diaphragm di-V end of each ofsaid levers engaging said inner cup member, and spring means urging saiddiaphragm, inner cup member and said other end of each of said levers inone direction.

2. A diaphragm pump as set forth in claim l, the said support memberbeing elongated and of plastic material for insertion into an engineopening, and means for attaching said support member to said engine.

aroma-a 3. A diaphragm pump having a casing, a diaphragm dividing theinterior of said casing into a pumping chamber and a vented actuatingchamber, one-Way pressure actuated valves arranged to serve said pumpingchamber, a support member xed to said casing and having an inner borenormal to the plane of said diaphragm and an exterior transverse groove,a plunger slidable in said bore, an inner cup member xed to saiddiaphragm Within said actuating chamber to move with said diaphragm,rocker levers Within said inner cup member and pivotally fixed to saidcasing, one end of each of said levers engaging said plunger to movetherewith, the other end of each of said levers engaging said inner cupmember, spring means within said inner cup member urging said diaphragm,inner cup member and said other end of each of said levers in onedirection and said transverse groove being adapted to orient saidsupport member in a given installation of said pump.

4. A diaphragm pump as set rorth in claim 3, the said support memberbeing elongated and of plastic material for insertion into an engineopening, and means for attaching said support member to said engine withthe use of said transverse groove.

5. A diaphragm pump having a casing, a pumping diaphragm dividing theinterior of said casing into a pumping chamber and a vented actuatingchamber, one-Way pressure actuated valves mounted in said casing toserve said pumping chamber, a support member fixed to said casing andhaving a bore normal to the plane of said diaphragm and communicatingwith said actuating chamber, a plunger slidable in said bore, means foractuating said diaphragm in one direction as a suction stroke includingan inner cup member fixed to said diaphragm and rocker levers pivotallyfixed with relation to said casing, one end of each of said leversengaging said plunger, the other end of each of said levers engagingsaid inner cup member, spring means within said inner cup member urgingsaid diaphragm in the opposite direction as a pumping stroke, and thearrangement being such that reciprocation of diaphragm through saidlevers and spring means is adapted to effect iluid iow through saidpumping chamber,

References Cited in the lc of this patent UNITED STATES PATENTS2,969,745 Johnson et al Jan. 31, 1961 3,016,840 Frick Jan. 16, 19623,025,550 Molenaar Mar. 20, 1962 FOREIGN PATENTS 1,057,297 France Oct.28, 1953 387,586 Great Britain Feb. 9, 1933

1. A DIAPHRAGM PUMP HAVING A CASING, A DIAPHRAGM DIVIDING THE INTERIOROF SAID CASING INTO A PUMPING CHAMBER AND AN ACTUATING CHAMBER, ONE-WAYPRESSURE ACTUATED VALVES ARRANGED TO SERVE SAID PUMPING CHAMBER, ASUPPORT MEMBER FIXED TO SAID CASING AND HAVING A BORE NORMAL TO THEPLANE OF SAID DIAPHRAGM, A PLUNGER SLIDABLE IN SAID BORE, AN INNER CUPMEMBER FIXED TO SAID DIAPHRAGM WITHIN SAID ACTUATING CHAMBER TO MOVEWITH SAID DIAPHRAGM, ROCKER LEVERS WITHIN SAID INNER CUP MEMBER ANDPIVOTALLY FIXED TO SAID CASING, ONE END OF EACH OF SAID LEVERS ENGAGINGSAID PLUNGER TO MOVE THEREWITH, THE OTHER END OF EACH OF SAID LEVERSENGAGING SAID INNER CUP MEMBER, AND SPRING MEANS URGING SAID DIAPHRAGM,INNER CUP MEMBER AND SAID OTHER END OF EACH OF SAID LEVERS IN ONEDIRECTION.